Think I ruined a great 486 motherboard. \ VOGONS

Think I ruined a great 486 motherboard.

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First post, by Rhuwyn

Posted on 2016-09-02, 21:02

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So like the subject says I think I ruined a perfectly good 486 motherboard. Went on a buying spree not too terribly long go and I ended up with two systems that use 72PIN SIMMs and a boatload of unknown 72PIN SIMMs. One system was a 486 and the other was a Pentium MMX. Being the min-maxer I am I wanted to test all the RAM to see what the RAM was and then make a decision on what RAM to leave in each system. In the process of inserting and removing dozens of SIMMs into the 486 board I think I ruined the contacts in the RAM slots. It won't post with any RAM now with either pair of slots.

Anyone ever have this issue? Anyone have success in fixing it.

Reply 1 of 10, by h-a-l-9000

Posted on 2016-09-02, 22:01

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If memory was the problem you should get beep codes from the PC speaker.

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Reply 2 of 10, by clueless1

Posted on 2016-09-02, 22:02

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Does it post with no ram? (I'm not sure that is possible?) Do you think it's possible that there was enough board flex during adding and removing ram that maybe some traces were damaged, rather than contacts? Either way, that sucks. 🙁

It wouldn't hurt to pull the board out and do a bare setup outside of the case just as a test.

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Reply 3 of 10, by adalbert

Posted on 2016-09-02, 22:07

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Did you try cleaning the slot and memory modules with alcohol? Also check if any of those little metal contacts is not bent or broken. Can you hear any beeps from the mainboard or is it completely silent? The worst option would be having the chipset killed by ESD because of frequent touching the mainboard, actually it happened to me once - I had a socket 7 maiboard on my desk, I was plugging and unplugging the IDE cables a lot, I was moving it around, and it just stopped working. No signal at all, no POST codes on the diagnostic card. Or maybe it was damaged mechanically due to bending when unplugging, but I'm not sure about that. I reflowed solder points on my mainboard but it didn't help.

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Reply 4 of 10, by h-a-l-9000

Posted on 2016-09-02, 22:44

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> Does it post with no ram? (I'm not sure that is possible?)

Without system RAM any PC compatible will not POST ( = show a BIOS screen) but ideally emit a beep code.

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Reply 5 of 10, by keenmaster486

Posted on 2016-09-02, 22:49

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h-a-l-9000 wrote:
> Does it post with no ram? (I'm not sure that is possible?)

Without system RAM any PC compatible will not POST ( = show a BIOS screen) but ideally emit a beep code.

Now that's a very useful fact which I did not know.

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Reply 6 of 10, by kixs

Posted on 2016-09-03, 03:06

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Does it have a speaker connected? Does it beep? Check error codes to see where is the problem. 486 most usually won't post with EDO ram (70ns are usually 90% FPM, 60ns is more like 60% EDO). Try using only one memory module and test it in each SIMM slot. On some 486 boards the order isn't important but on some it has to be in the 1st slot otherwise it won't boot.

Also reinsert other cards.

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Reply 7 of 10, by nforce4max

Posted on 2016-09-03, 04:33

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As slots wear out this happens so inspect the contacts and give it some cleaning, if you get the board running again do not change the memory and just leave it alone from then on.

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Reply 8 of 10, by Rhuwyn

Posted on 2016-09-03, 16:14

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It looks like the actual metal trace is bent on one of the slots. The others I dont see visible damage. I am going to test the SIMMs in the Pentium MMX sytem being a lot more carefull. Does anyone know of a utility to identify Fast Page vs EDO and the speed?

Reply 9 of 10, by h-a-l-9000

Posted on 2016-09-03, 18:00

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Google is the tool. Search for product numbers of the sticks or chip markings. With some luck you get a product description.

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Reply 10 of 10, by kixs

Posted on 2016-09-03, 19:19

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I do it the "hard" way 😉

Test all 72-pin memory modules on Pentium and on the boot screen it says what type it is. Of course Pentium requires modules in pairs.

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